16 December 2010, Computational Social Choice Seminar, Floor Sietsma
Email is by now a prevalent form of communication. There is a great deal of information present in the emails people send and receive. We present a formal framework to investigate the epistemic consequences of email communication. Our central question is: after a certain email conversation has taken place, who knows what? This is an interesting question in a variety of settings. One example is a large company that finds out that a certain employer secretly works for a competitor and wants to investigate what secret information has been revealed to this employer. We give a history-based semantics for modeling email communication, and a logic to reason about it. We show that we can precisely characterize when a group of agents gains common knowledge and we give a partial decidability result of our logic.